The reference range will vary, depending on the age, sex and race of a population, and even the instruments the laboratory uses to perform the tests. Furthermore, by definition, 5% of the normal population will fall outside the reference range. The values given below therefore are given as examples only and should not be used to interpret individual test results. Factors other than medical conditions can affect laboratory values, such as male or female sex, diet, use of drugs (prescribed, over-the-counter and herbal remedies), and stress, as well as other more exotic factors like altitude.